The invention relates to an extension plug-in unit comprising a female connector coupled to a first cable and a male connector coupled to a second cable, which connectors comprise contacts arranged to establish an electrical connection, the connectors forming a hinge joint when connected together.
Extension plug-in units are usually cylindrical in shape, which means that the cables are connected together by inserting the connectors into each other. Thus the size of plug-in units intended for high currents increases to such an extent that it is difficult to handle the connectors and to insert them into each other due to the great frictional forces resisting the insertion.
Further, with cylindrical connectors it is difficult to set up an arrangement where a cable should be branched. The branching requires connections where an additional end with its connectors is branched off from the cable, and it is possible to further couple other units to this end. Such a branching arrangement is rather inflexible in practice and requires a great number of connectors.
In a prior art arrangement, the connectors of the extension plug-in unit are coupled by a hinge-type coupler. The connectors have the shape of a cylinder cut in two where contacts are provided on the cut surface. The hinge is formed at one end of the connectors to be coupled, such that when the connectors are pressed together around an axis of revolution formed by the hinge, the contacts produce an electrical connection. The problem with the extension plug-in units described above is especially how to form the contacts of the female connector in an advantageous and yet reliable manner. According to the prior art, the contacts of the female connector are formed of opposite contact sheets which are spring loaded in order to provide a reliable electrical connection and the compliance required for the coupling. Thus the contacts of the male connector are able to press between the opposite contact sheets of the female connector to form an electrical connection. The female contacts described above have a rather complicated structure and they are thus relatively expensive to manufacture.
The purpose of the present invention is to provide an extension plug-in unit which avoids the aforementioned drawbacks and enables the coupling of cables in a reliable manner but with a simpler connector structure than previously. This is achieved with an extension plug-in unit according to the invention, which is characterized in that the hinge joint enables the coupling of the contacts by means of a lateral turning movement that makes the connectors parallel to one another, the connectors comprising stepped inner surfaces whose opposite mating surfaces are provided with the contacts, so that during the turning movement the flexibly supported wedge-shaped contact pins of the male connector press into the contact recesses of the female connector to establish an electrical connection.
The extension plug-in unit according to the invention is based on the male and the female connector being connected by means of a hinge joint. The hinge joint is formed such that the connectors are placed parallel to each other by turning them in the lateral direction. The contacts of the connectors are then able to form an electrical connection together. The contacts are provided on the inner surfaces of the connectors that are pressed together, and the male contacts are wedge-shaped and flexibly supported on the connector. The female connectors, in turn, are v-shaped recesses which are able to receive, during the coupling, the flexibly supported male connectors to form a reliable electrical connection.
The advantage of the connector according to the invention is its reliability which is achieved in the cable coupling by means of a minimal physical force. Further, the structure of both the male and the female connector is simple, wherefore the connectors can be manufactured with simple technology and low costs.